<html xmlns="http://www.w3.org/1999/xhtml">

<head>
  <meta charset="utf-8" />
  <link rel="stylesheet" href="popup.css" />
</head>

<body>
  <input type="button" value="按钮" id="changeColor" />
  <input type="button" value="清空" id="clearBtn" />
  <input type="button" value="自动播放" id="autoPlay" />
  <!-- <hr>
  <input type="button" value="按钮1" id="btn1" /> -->
  <hr>
  <ul id="myul">
  </ul>
</body>
<script src='popup.js'></script>

</html>